Idaho state health officials have announced that a child in the state has a confirmed diagnosis of bubonic plague. The child became ill late last month and has now received antibiotic treatment and is recovering. The Central District Health Department did not reveal the child’s name, age or gender.

Health officials say that this was the first human plague case in the state in more than two decades. The most recent cases in the state were reported in 1991 and 1992. Officials are unsure whether the child from Elmore County was exposed to plague in Idaho or during a recent trip to Oregon. Since 1990, eight human cases have been confirmed in Oregon and two in Idaho.

While human infection is rare, people still catch the plague every year in the US, usually after coming into contact with fleas that carry plague bacteria. There is usually between one and 17 cases across the country every year. The cases mostly occur in the rural West and the Southwest.

Plague is spread by fleas that carry the Yersinia pestis bacteria. The bacteria can cause three forms of plague: septicemic, bubonic, and pneumonic. Septicemic plague is an infection of the blood that causes skin and tissue to turn black and die. Bubonic plague is characterized by painfully swollen lymph nodes. Untreated, patients can develop pneumonic plague, which is based in the lungs, “is the most virulent form of plague” and “can be fatal” when not diagnosed and treated early on, according to the World Health Organization.

Symptoms of plague usually occur within two to six days of exposure and include headache, fever and chills, and extreme weakness. Those with bubonic plague may also experience swollen lymph nodes or buboes in the groin, armpit, or neck. Those with pneumonic plague may experience pneumonia along with chest pain, coughing and trouble breathing. Pneumonic plague can spread from person to person when infected people cough the bacteria into the air.

Plague signs in cats and dogs include fever, lethargy and loss of appetite. The pet may also experience a swelling in the lymph nodes under the jaw. Prompt diagnosis and appropriate antibiotic treatment can greatly reduce the risk of death in both people and pets.